Journal of Applied Physiology, Vol 62, Issue 6 2300-2307, Copyright © 1987 by American Physiological Society
Estimation of equivalent pore radii in pulmonary microvasculature after lung lymph fistula preparation
L. Smith, S. Andreasson, K. T. Tolling, B. Rippe and B. Risberg
The effect of lung lymph fistula preparation on pulmonary microvascular
permeability was investigated in sheep. Acutely prepared animals (n = 9)
were compared with animals with a chronic lung lymph fistula (n = 5). The
osmotic reflection coefficients (sigma) for total protein, albumin,
immunoglobins (Ig) G and M, and the equivalent pore dimensions were
calculated. Data were achieved at maximal possible lymph flows (QL)
following elevation of left atrial pressure. In sheep with a chronic lung
lymph fistula sigma's for total protein, albumin, IgG, and IgM at maximal
lymph flows were 0.76 +/- 0.01, 0.65 +/- 0.09, 0.79 +/- 0.03, and 0.91 +/-
0.01, respectively. In the acutely prepared group the minimum
lymph-to-plasma protein concentration for total protein was 0.39 +/- 0.06,
corresponding to a sigma of 0.61 +/- 0.01. The sigma for albumin, IgG, and
IgM were 0.48 +/- 0.04, 0.64 +/- 0.02, and 0.87 +/- 0.01, respectively. The
equivalent pore radii in the chronic group were determined to be 54 and 190
A with 29% of the filtration accounted for by large pores. In the acute
group the small pores were 56 A and the large pores 175 A with 53% of total
volume flow at maximum lymph flows occurring through the large pores.
Assuming a constant small-pore population the large pore number increased
4.5 times after surgery. For total protein, IgG, and IgM, sigma's in the
acutely prepared group were significantly lower than in the control group.
These results thus indicate that surgical preparation of a lung lymph
fistula in sheep may cause acute increases in pulmonary microvascular
permeability.
